Integrated Design System for Building and General Structures · 2016-09-17 · Gen 2011 New module...

Gen 2011 (v1.1) Release NoteIntegrated Design System for Building and General Structures

Enhancements

1. Addition of Header and Footer in Dynamic Report

2. Midas Link for Revit Structure 2011

3. Plate Member Data in the Model Data Text Output

and much more…

Pre/Post Processing

Analysis

New module

1. Pushover analysis enhancement

1) Lateral load pattern as per N2 method

2) Target displacements as per NTC 2008

3) Safety Verification as per NTC 2008

4) Enhanced Safety verification Table

2. Damping Ratios by Material Properties

3. Considering Consistent Mass in Time History Analysis

and much more…

1. General Section Designer

16

3

22

Design

1. Enhancement in Strong Column-Weak Beam Design as per TWN-USD92

41

1. General Section Designer

New Module

Gen 2011 New module (GSD)

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Gen 2011 (v1.1) Release Note

General Section Check or GSD is a new module added to midas Civil/Gen.

Scope of GSD: Definition of any irregular cross-section

Calculation of Section properties

Generation of P-M, P-My-Mz, M-M interaction curves

Calculation of Section Capacity (in flexure) and Safety Ratio based on member forces.

Generation of Moment-Curvature curve.

Plot of Stress contours for all the cross-sections.

All the above features are supported for: RC sections, Steel sections and Composite sections.

1. General Section Designer (GSD)

Stress ContourWork process

Moment- Curvature3D PM Interaction curve


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User Interface

• GSD can be called from midas Gen by Tools > General Section Designer.

• In one model file, more than one section can be created and saved under different names.

• All the sections are listed in the Works Tree.

• Double click the section name in the Works Tree to show the section in the section view .

Toolbar

Coordinates

Main menu Works Tree

Message Window Unit ControlTable Window

Section View


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Work Process

Step 1. Define material

• Materials : RC, Steel.

• Applied Codes: Eurocode, UNI, British Standard, ASTM, Indian Standard, etc.

• Nonlinear material properties can also be assigned to concrete, structural steel and rebar

materials.


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Work Process

Step 1. Define material

• Nonlinear Material Properties

Kent & Park ModelParabolic Stress-strain Curve

• Concrete nonlinear properties

• Steel nonlinear properties

Menegotto-Pinto Model Asymmetrical Bi-linear Curve


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Work Process

Step 2. Define cross-section

– Basic shape section by selecting a section from the DB of the standard sections for a

country

– Any irregular cross-section by specifying the shape in the Section View or entering

coordinates into a table

General type shape

Model > Shape > Basic Shape


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Work Process

Step 2. Define cross-section

– Merging two shapes

– Creating hollow sections

Copy Shapes

Creating Hollow Section

Merged Shapes

Model > Shape > Merge Shape


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Work Process

Step 3.1 Select Rebar Material

• The following stress-strain curves can be assigned to rebars.

– Elastic-Only

– Bilinear Model

– Menegotto-Pinto Model

– Park Strain Hardening

Menegotto-Pinto ModelPark Strain Hardening

Model > Rebar > Rebar Material

Bilinear Model


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Work Process

Step 3.2 Add Rebars: Various patterns are available for assigning the rebars to a section.

– Point pattern : Add rebar at a single point.

– Line Pattern : Add rebars in a line.

– Arc Pattern : Add rebars in a circular arc patterns.

– Rectangular Pattern : Add rebars in a rectangular pattern.

– Perimeter pattern : Add rebars around the outer perimeter of the section by

specifying the concrete cover and number of rebars.

Model > Rebar > Rebar-Point Pattern…


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Work Process

Step 4. Define Load Combinations and member forces

Sign Convention:

• Clockwise moment about the y and z axes are taken as positive. Anti-clockwise moments

are taken as negative. P is taken as positive towards ‘+z’ axis.

Step 5. Cross-section Properties:

• Apart from general section properties, Principal Properties, Section Modulus & Plastic

properties are also calculated.

Model > Define Load Combination

Model > Section Property


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Work Process

Step 6.1 Check Results: Interaction Curves

Result > Interaction curve

P-M interaction curve for a specified angle

P-M interaction curve for a Load Combination


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Work Process

Step 6.1 Check Results: Interaction Curves

Result > Interaction curve

M-M interaction curve for a Load combination

3 D interaction surface showing all the load combination


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Work Process

Step 6.2 Check Results: Moment-curvature curve

Step 6.3 Check Result: Stress Contour

Result > Moment Curvature Curve

Moment-curvature curve

Stress contours

Move mouse pointer onthe curve to see thestrain diagram at aparticular point.

Result > Stress Contour




4. Easy access to the Time History Result Tables

5. Warning Message for the Changes in the Story Data

List of Detailed Enhancements in Pre & Post Processing

Gen 2011 Pre & Post-processing Gen 2011 (v1.1) Release Note

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1. Fill out the Project Information in the File tab.

2. Open the Dynamic Report and double click Header and Footer in the Report Tree.

3. Select the items to add or remove in the header or footer field by clicking arrow buttons.

4. Use up and down arrows to arrange the order of header and footer items.

5. Click OK button to confirm.


In the dynamic report, we can add the project Information in the header and footer of MS

Word. Project Information includes Project Name, Revision, User Name, E-mail, Address,

Telephone, Fax, Client, Title, File Name, Created, Directory, Modified, and File Size.

Procedure of Header and Footer Generation

Tools > Dynamic Report Generator


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1. Send the Revit Structure analytical model to midas Gen

2. Import the MGT file of the Revit model in midas Gen

3. Export the midas model file to the MGT file

4. Update the Revit Structure model from midas Gen


Midas Link for Revit Structure 2011 is now available to transfer a Revit model data to midas

Gen, and delivery back to Revit model files. It is provided as an Add-In module in Revit

Structure and midas Gen text file(*.mgt) is used for the roundtrip.

Midas Link for Revit Structure supports the following workflows

Tools > Dynamic Report Generator


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• Now ‘Plate Member Data’ can viewed in the Model Data Text Output.

File > Model Data Text Output > Plate Member Data


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5. Easy Access to the Time History Result Tables

• Time History Result Tables have been added to the Context Menu for improved

accessibility.

Context Menu > Time History Results > Inelastic Hinge Table / Time History Analysis Table

Disp./Vel./Accel. Table

Beam Force Table


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6. Warning Message for the Changes in the Story Data

• A warning message is displayed notifying that the number of stories being considered is

not in agreement with the generated data.

Model > Building > Story

• After Story Data generation

when a node is moved (the node where a story is assigned is edited)

when a story is added

when a story is divided

• The following message will be displayed when executing Perform Analysis








4. Improvement in Group Damping

5. Considering Static Load Case for the Initial Loading in

Time History Analysis

6. Considering the Construction Stage Load for Initial

Loading in Pushover Analysis

7. Option for cumulating reactions and displacements

due to initial loads in Pushover Analysis

8. Considering Boundary Change Assignment Function

in Pushover Analysis

9. Option for Considering the Shear Failure in Pushover

Analysis

10. Improvement in Pushover Hinge Properties with SRC

Sections

11. Addition of Ramberg-Osgood and Hardin-Drnevich

Models in Inelastic Hinge Property

List of Detailed Enhancements in Analysis

Gen 2011 Analysis

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• The N2 method implements a new load pattern Normalized Mode Shape * Mass for

Pushover analysis.


Design > Pushover Analysis > Pushover Load Case


Gen 2011 Analysis

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• Eigenvalue analysis is performed to obtain the mode shape for pushover analysis on a

structure. In midas Gen, the mode shapes are normalized in such way that Φn=1, where n is

the user defined master node , generally at the roof level.

• Pushover analysis is complete when the displacement of the master node reaches the

specified maximum displacement. The lateral loads are applied at the centre of mass of each

storey and the lateral load pattern is obtained by the normalized Ф values of centre of mass.

• The mode shape values of a structure, at the center of mass, are specified in the table along

with the normalized values.

.87

.65

.54

.21

.74

.63

.24

1

Model Mode Shape Normalized Mode Shape

StoryMode Shape

ФNormalized Mode Shape Ф

Roof .87 1

3F .65 .74

2F .54 .63

1F .21 .24

Normalization of Mode Shape

User-Defined Master Node

Normalization of mode shape

1F

2F

3F

Roof

Gen 2011 Analysis

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Lateral Load Pattern

• In order to generate pushover curves, lateral load patterns are required. If floor

diaphragms are assigned, lateral loads are applied at the center of mass per story. If floor

diaphragms are not assigned, lateral loads are applied at the location of the masses in the

model automatically.

• The pushover load is applied up to the point when the displacement of master node

reaches the maximum displacement.

• The lateral load patterns are obtained by normalized mode shape and Story mass factor.

Model

m4 = 400

.74

.63

.24

1

Normalized Mode Shape

1

.55

.31

.06

Load Pattern

Story Story MassNormalized Mod

e Shape, ФCalculation Load Factor

Roof 400 1 (1X400)/(1X400) 1

3F 300 .74 (.74X300)/(1X400) .55

2F 200 .63 (.63X200)/(1X400) .31

1F 100 .24 (.24X100)/(1X400) .06

Lateral Load Pattern

m3 = 300

m2 = 200

m1 = 100 1F

2F

3F

Roof

Gen 2011 Analysis

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Gamma Calculation

• Transformation factor Gamma is calculated based on the following two methods:

o 2D Behavior (EC8-1:2004 Annex B)

o 3D Behavior

• 2D Behavior is based on EC8 -1 :2004 Annex B and determines the value of gamma by only

considering the direction in which pushover analysis is performed . Hence the value of

gamma is :

• 3D Behavior determines the gamma by considering lateral deflection in all the possible

directions :

Design > Pushover Analysis > Pushover Curve


Gen 2011 Analysis

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• Target displacements are defined as the seismic demand derived from the elastic response

spectrum in terms of the displacement of an equivalent SDOF system. Target displacements

for the limit states SLO, SLD, SLC and SLV are automatically calculated as per NTC2008.

Different spectrums can be assigned to different limit states for determining the demand.


Select spectrum for different limit states

Target displacements and corresponding pushover steps


Target displacements and corresponding pushover stepsMethod of Gamma Calculation


Target displacements and corresponding pushover steps


Target displacements and corresponding pushover stepsMethod of Gamma Calculation

Gen 2011 Analysis

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• The interstory drift demands from pushover analysis should not exceed the corresponding

capacities. Global verification is performed for the limit states SLO and SLD.

• Interstory drift limit values are:

- SLD: 0.005h, SLO: 0.005h x 2/3, where h is the story height.

• The interstory drift demands are represented by target displacements for SLD and SLO. The

capacities for SLD and SLO are determined by the roof displacements when maximum

interstory drift is equal to its limit values, 0.005h and 0.005h x 2/3, respectively.


Global verification ( = Limitation of interstory drift)

Demand and capacity table

Gen 2011 Analysis

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The local ductility and deformation demands from pushover analysis should not exceed the

corresponding capacities which implies that brittle elements should remain in the elastic

region. Local verification is performed for the limit states SLD, SLV and SLC. The capacities are

determined as shown in the table below. The demand (rotation or shear force) for a member is

obtained from the pushover step which is nearest to the target displacement for the

corresponding limit states.

Demand and capacity table

Local verification

Design > Pushover Analysis > Pushover Hinge Result Table > Safety Verification Table

Gen 2011 Analysis

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• Capacity values for different limit states can be viewed with user defined steps.

Design > Pushover Analysis > Pushover Hinge Result Table > Safety Verification Table

Capacity values

Gen 2011 Analysis

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• An option considering different damping ratios for different materials has been added in

the Material Data for time history analysis and response spectrum analysis.

• In order to apply the damping ratio specified in the Material Data, following damping

method needs to be selected in the Time History Load Cases.

Response Spectrum Analysis : Strain Energy Proportional

Time History Analysis: Element Mass & Stiffness Proportional or Strain Energy Damping

Model > Properties > Material > Add > Damping Ratio

Load > Time History Analysis Data > Time History Load Cases

Default value of damping ratio by material types

- Steel : 0.02 (2%)- Concrete / SRC : 0.05 (5%)- USER : 0.00 (0%)

Gen 2011 Analysis

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• Now Consistent Mass and Off-diagonal Masses option of Lumped Mass can be

considered during the linear and nonlinear time history analysis. In the previous

versions, ‘Lumped Mass’ could be applied only when selecting the ‘Off-diagonal Masses’

option in the time history analysis.

• If the Consistent Mass or Off-diagonal Mass option is used, Lanczos method should be

used for Eigenvalue Analysis.

Model > Structure Type

Consistent Mass

Mass Offset (Off-diagonal Masses)

Gen 2011 Analysis

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4. Improvement in Group Damping

• Group Damping dialog box has been divided into ‘Element Mass & Stiffness

Proportional…’ and ‘Strain Energy Proportional…’.

• Now Mass Coefficient (alpha) can be considered. Coefficients for mass and stiffness

(alpha and beta) are automatically calculated.

Model > Properties > Group Damping : Element Mass & Stiffness Proportional

Model > Properties > Group Damping : Strain Energy Propotional

Element Mass & Stiffness Proportional

Strain Energy Proportional

Gen 2011 Analysis

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5. Considering Static Load Case for the Initial Loading in Time History Analysis

• Now Static Analysis Result ‘Import (ST)’ can be considered as an initial load.

• In the previous versions, the axial force due to ‘ST’ initial load was not reflected when

determining yielding of the hinge. In the new version, the axial force due to ‘ST’ initial load is

reflected when calculating the yield strength of moment component.

• When ‘Increment Method>Load Control’ is used, ‘Time History Load Cases>Scale Factor’ is now

reflected.

Load > Time History Analysis Data > Time History Load Cases

Gen 2011 Analysis

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6. Considering the Construction Stage Load for Initial Loading in Pushover Analysis

• Final stage member forces from construction stage analysis can be used as initial loads

for the pushover analysis.

Pushover Analysis > Pushover Analysis Control

Gen 2011 Analysis

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7. Option for cumulating reactions and displacements due to initial loads

in Pushover Analysis

• In the previous versions, reactions due to initial loads were cumulative whereas

displacements due to initial loads were not cumulative.

• Now the user can choose whether to cumulate reactions/displacements due to initial

loads or not.

Design > Pushover Analysis > Pushover Analysis > Pushover Load Cases

• When the initial load filed is displayed as

‘Import ST/CS Result’, this option is not

available.

Note that the results from the new version

may not be the same as that from the

previous version of midas Gen because of

this option.

• In the previous versions, the results due to

initial loads were

For Reaction/Story shear: cumulative

For Displacement: not cumulative

Gen 2011 Analysis

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8. Considering Boundary Change Assignment Function in Pushover Analysis

• This function can be applied to the following condition:

- When the boundary condition of the initial loading is different from that of the pushover loading

- When the section stiffness scale factor assigned for the initial loading is different from that of the

pushover loading

Analysis > Boundary Change Assignment to Load Cases/Analyses

Gen 2011 Analysis

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9. Option for Considering the Shear Failure in Pushover Analysis

• New option for considering the shear component failure has been newly added. When the

option is selected, the analysis will be automatically terminated if the shear hinge occurs in the

selected member type.

Design > Pushover Analysis > Pushover Global Control

Gen 2011 Analysis

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10. Improvement in Pushover Hinge Properties with SRC Sections

• Pushover hinge properties can be calculated automatically for the following SRC sections: Rect-

Cross I / Rect –Combined T / SRC-BOX-Stiffener / SRC-Pipe-Stiffener

Design > Pushover Analysis > Define Hinge Properties

Gen 2011 Analysis

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11. Addition of Ramberg-Osgood and Hardin-Drnevich Models in Inelastic Hinge Property

• Inelastic Hinge Properties can be defined with the Ramberg-Osgood and Hardin-

Drnevich models and applied for inelastic time history analysis for soil.

Model > Properties > Inelastic Hinge Properties

Ramberg-Osgood, Hardin-Drnevich Hysteresis Curve


List of Detailed Enhancements in Design

Gen 2011 Design

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• A new option for Strong Column-Weak Beam design has been added.

• In the previous version, beam design strength (ΦbMnb) calculated the design flexural

member force in column. In the new version, the design strength (ΦbMnb) or the

nominal strength (ΦbMnb) can be considered.

Design > RC Strong Column Weak Beam Design > Ductile Design

Design > RC Strong Column Weak Beam Design > Strong Column Weak Beam Ratio

Design > RC Strong Column Weak Beam Design > Strong Column Weak Beam Ratio Table

Gen 2011 Design

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Ductile Design

When Design Strength is selected When Nominal Strength is selected

Strong Column Weak Beam Ratio

Design > RC Strong Column Weak Beam Design > Ductile Design

Concrete Code Design > Beam Design, Column Design

Concrete Code Check > Beam Checking, Column Checking

Design > RC Strong Column Weak Beam Design > Strong Column Weak Beam Ratio

When Design Strength is selected When Nominal Strength is selected

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Integrated Design System for Building and General Structures · 2016-09-17 · Gen 2011 New module...

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